Researchers at Yashraj Biotechnology Ltd. purified and characterized neutrophil gelatinase associated lipocalin (NGAL), a key biomarker of acute kidney injury, from the urine of AKI patients (kNGAL) and from healthy human neutrophils (nNGAL). Using 2D electrophoresis, MALDI-TOF/TOF, ELISA and western blot, the study showed that kNGAL is slightly acidic and mainly monomeric, whereas nNGAL occurs as both monomers and dimers across a wide pI range, and that kNGAL is more highly sialylated. These differences suggest distinct roles for NGAL under different disease conditions and are relevant to the design of NGAL immunoassays.